Cab signal and speed control for locomotives

ABSTRACT

Each locomotive in a railroad classification yard area is provided with both cab signal and automatic speed control apparatus, each element controlled at different times from a remote location. The cab signal or speed commands are transmitted to a locomotive by one or a combination of selected tone signals modulated on a carrier signal. Remote control of all cab signals may be by the humpmaster but normally one locomotive is assigned to humping operations and control of its cab signal transferred to the hump conductor. Remote automatic speed control can be established on a locomotive only when it is assigned to humping operations. That locomotive speed control apparatus is then controlled by transmitted tone combinations corresponding to speed selections made by the humpmaster. The locomotive engineer must acknowledge a received automatic operation request in order to establish the remote control condition on the locomotive. The engineer retains an ability to restore local onboard control at any time and has final control of reestablishing automatic operation after any interruption.



1. In a railroad classification yard, including a humping track over which cars are moved for selective classification, a system for controlling the operation of the hump locomotive, comprising in combinations, a. signal transmitting means on the wayside for transmitting over a predetermined channel combinations of a plurality of tones as operating commands to said hump locomotive, b. a cab signal indication sElector means on said wayside operable, and normally connected, for controlling said signaltransmitting means to actuate the transmission of selected tone combinations designating desired cab signal indications, c. a locomotive speed selector means on said wayside connected to said signal-transmitting means at selected times to bypass said cab signal selector means and operable at said times for controlling said transmitting means to actuate the transmission of other selected tone combinations designating desired speed ranges for the remote control of said locomotive, d. automatic control selection means on said wayside operable at said selected times to a remote locomotive speed control condition and connected for transferring at said times the control connections of said transmitting means from said cab signal selector means to said speed selector means, e. a receiver means on said locomotive coupled for receiving and registering the tone combination transmitted by the signal transmitting means, f. speed control means on said locomotive connected for controlling the speed of that locomotive and selectively operable to a manual and a remote control condition,
 1. said speed control means coupled to said receiver means and responsive to the received tone combination only when actuated into the remote control condition for controlling the locomotive speed in accordance with that combination, g. the operation of said speed selector means following a transfer of the control connections of said transmitting means to said speed selector means actuating the transmission of a distinct initial signal request for establishing a remote control condition of said speed control means, h. an acknowledging means on said locomotive connected to said receiver means and said speed control means and operable only when an initial signal has been registered for establishing the remote control condition of said speed control means, and i. cab signal apparatus on said locomotive connected to said receiver means and responsive to registered tone combinations in the absence of an established remote control condition for guiding a locomotive operator in controlling said locomotive.
 2. A hump locomotive control system as defined in claim 1 in which said combination further includes, a. detector means in said humping track for detecting the immediate approach of a train being classified, b. said detector means connected for completing the connections of said speed selector means to said signal transmitting means only when a train is detected in the immediate approach on said humping track.
 3. A hump locomotive control system as defined in claim 1 in which said acknowledging means comprises: a. a registry relay controlled by said receiver means for temporarily registering the reception of an initial signal, b. acknowledging devices operable for actuating the storage of a received initial signal, c. a storage means controlled by said registry relay and said acknowledging devices for storing an initial signal registry when that signal has been received and said devices have been operated, and d. a stick circuit for said registry relay effective for holding the temporary registry of an initial signal until its storage is actuated if the transmission of another tone combination prematurely replaces said initial signal prior to the operation of said devices.
 4. A hump locomotive control system as defined in claim 3 in which said storage means includes, a. a stick relay controlled by said acknowledging devices and said registry relay for receiving and holding said temporarily registered initial signal when said devices are operated, b. a stop signal relay controlled by said receiving means and responsive to the absence of all tones, c. a memory relay controlled by said stick relay for storing an indication of an initial signal storage and by said stop signal relay for holding said indication as long as aNy tone combination is thereafter received, and d. a supplemental circuit for said registry relay jointly controlled by said stick relay, said stop signal relay, and said memory relay for reentering an initial signal registry if the acknowledgment of the previous registry is withdrawn while any tone combination continues to be received.
 5. A hump locomotive control system as defined in claim 4 in which said system combination further includes a temporary stop control means comprising, a. a control circuit connection responsive to the operation of said cab signal selector means to a stop condition, when said automatic control means is in its speed control condition, for interrupting the control of said transmitting means by said speed selector means to halt the transmission of all tone combinations and activate a temporary stop condition on the hump locomotive, b. a temporary stop register means controlled by said cab signal selector means and said automatic control means for registering the temporary stop condition,
 6. In a railroad classification yard system including, a track lead with a hump over which trains are moved for classification, a plurality of switching locomotives each assignable to humping operations, wayside signals along said track lead for displaying a selected one of a plurality of signal indications to at times direct the movement of the assigned hump locomotive; a hump locomotive movement control system comprising in combination, a. a first wayside control means having connections to said wayside signals and selectively operable for controlling the signal indication displayed to direct the desired manually controlled movement of the assigned hump locomotive, b. signal-transmitting means at the wayside for transmitting when actuated selected signal combinations to each locomotive, each combination being receivable only by the corresponding locomotive, c. a second wayside control means operable for selecting one of said plurality of locomotives for humping operations and for completing control connections between said first control means and said transmitting means by which the transmission of signal combinations receivable by only the selected humping locomotive may be actuated by said first control means to also direct the manually controlled movements of that locomotive, d. speed control means on each locomotive for at times automatically maintaining the movement of the corresponding locomotive within a selected one of a plurality of predetermined speed ranges, e. signal-receiving means on each locomotive for selectively receiving from said transmitting means only the signal combinations intended for the corresponding locomotive and having connections to the associated speed control means for at said times selecting one speed range of said plurality of speed ranges in response to the received signal combination, f. a third wayside control means operable for transferring the control connections of said signal-transmitting means from said first control means to said third control means and connected for immediately thereafter actuating said transmitting means to transmit an initial request signal combination to the selected hump locomotive, g. said third wayside control means subsequently operable to select different ones of said predetermined speed ranges and controlling said transmitting means to actuate the transmission of signal combinations correSponding to the existing selected speed range, and h. acknowledging means on each locomotive controlled by the corresponding receiving means for indicating the reception of an initial request signal by that locomotive and operable thereafter for activating the control of the associated speed control means by the corresponding receiving means.
 7. A hump locomotive movement control system as defined in claim 6, in which said combination further includes, a. a train detector in said track lead immediately in approach to said hump operable for detecting the approach of a train to be classified, b. said train detector connected for controlling said third control means to complete its connections to said transmitting means only when the approach of a train has been detected.
 8. A hump locomotive movement control system as defined in claim 7 in which said third control means is further operable for actuating the transmission of a signal combination corresponding to a stop speed command for cancelling control of said speed control means by said receiving means.
 9. A hump locomotive movement control system as defined in claim 8 in which said third control means comprises, a. an automatic operation control means operable for establishing the wayside control condition necessary to transfer control of the hump locomotive speed control means to the associated receiving means, b. a speed range selector device for selecting a signal combination corresponding to the initial signal and subsequently other signal combinations corresponding to the plurality of speed ranges for the hump locomotive, c. a registry stick relay controlled by said automatic control means, said selector device, and said first and second control means for registering the establishment of said control condition when jointly said initial signal is selected, said first and second control means occupy cooperating positions, and said automatic operation control means is operated to establish said control condition,
 10. A hump locomotive movement control system as defined in claim 9, in which said third control means also includes a. a temporary stop register relay controlled by said first control means and said condition registry stick relay for registering operation of said first control means out of its cooperating position when a wayside control condition has been registered to briefly halt the hump locomotive, b. a stick circuit for said temporary stop register relay completed by said first control means in its cooperating position and said condition registry relay in its nonregistering position, c. a signaling circuit means controlled by said temporary stop registry relay in its registering position and said first control means in its cooperating position, d. said signaling circuit means connected for actuating when completed another transmission of an initial request signal combination, thereby reestablishing the wayside control condition registry and reactivating control of the hump locomotive speed control means by the associated receiving means.
 11. A hump locomotive movement control system as defined in claim 10 in which, said signal combinations transmitted by said transmitting means comprise a basic carrier signal modulated by a selected combination of tones. 